Rotary loop taker



Dec. 21, 1937, R. K, HOHMANN 2,102,954

ROTARY LOOP TAKER Filed March 2, 1957 ATTO R N EY Patented Dec. Z1, 1937.Y UNITED STATES PATENT OFFICE 7 Claims.

The general object of the present invention is to provide an improvedrotary loop taker for use in sewing machines of the rotary hook type.

A more specific object of the invention is to provide improvementssimplifying and cheapening the construction of a loop taker adapted toreceive a bobbin carrier of standard construction. Another specic objectof the invention is toprovide a rotary loop taker of the type comprising1G a hook ring formed separately from, and detachably connected to aspider or hub portion of the hook member, and which is specially shapedto adapt the loop taker for the use therewith of a bobbin carrier oflarger diameter relative to the hook ring diameter than has heretoforebeen possible. Another specific object of the invention is to provide arotary loop taker with a detachable part of novel form and comprising aloop deflecting edge and a loop discharging spur.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, and specific advantages attained with its use, reference should`be had to the accompanying drawing and descriptive matter in which Ihave illustrated and described a preferred embodiment of the invention.

Of the drawing:

Fig. lv is an elevation, partly broken away and in section, of a rotaryloop taker;

Fig. 1A is a plan of a portion of the loop taker shown in Fig. l;

Fig. 2 is a section onv the broken line 2 2 of Fig. 1

Fig. 3 is a section on the line 3-3 of Fig. l; Fig. 4 is a perspectiveview, with parts broken away and in section, illustrating the manner oin which the bobbin carrier is moved into and out of operative relationwith the hook ring;

Fig. 5 is a perspective view of the hook ring and a loop deflecting anddischarging spur part detachably connected to the hook ring;

.l5 Fig. 6 is an elevation of a loop taker of modified construction;

Fig. 7 is a section on the line 'l--l of Fig. 6.

My improved loop taker, in the form illustrated in Figs. 1 to 5,comprises a hubor spider mem- A50 ber A, which is formed with an axialopening A in which the sewing machine rotary hook shaft (not shown) isnormally secured. The member A is formed at its periphery with aforwardly extending rim or cylindrical flange A2 which in `55 theassembled condition of the loop taker, is

snuglybut removably received within the hook ring B, the latter beingnormally secured to the spider member A by screws C. The hook ring B iscut away at its front side to form the loop taking hook, or beak, B',and a hook notch B2, which comprises a, portion angularly in advance ofthe hook B', and a portion alongside the inner edge B3 of the hook. y

The hook ring notch B2 is bridged by an arc shaped part E normallyhaving its ends received 10 in recesses B4 and B5 formed in the outerside of the hook ring at opposite sides of the notch B2, the ends of thepart E being detachably secured in said recesses by screws. The member Eis shaped to provide a thread deflectingedge E 15 inclined relative to aplane transverse to the loop taker axis, at an angle opposite to that atwhich the rear edge B3 of the loop hook B' is inclined. The member Ealso comprises an integral loop discharging spur E2, facing and adjacentthe hook B', but having its point angularly '20 in advance of the pointof the hook, having reference to the direction of the rotative movementof the hook. As is shown in Fig. 1A, the innerside o-f the base portionof the tapered spur E2 is well to the innerside of the hereinaftermentioned bearing rib D of the bobbin carrier D, so that the spur E2 isadapted to hold a thread loop engaging the innerside of its base portionout of engagement with said bearing rib D.

The formation of the loop deflector E and discharging spur E2 byintegral portions of a part detachably connected to loop taker body orhook ring contributes to mechanical simplification and reducedmanufacturing cost. The constructionV illustrated is advantageouslycharacterized, moreover, by special provisions for accurately securingthe part E in place on the hook ring and for guiding the thread atpoints where the edge E and spur E2 merge into thread engaging edgeportions of the hook ring. Thus at the rear end 40 of the loop deectingedge E', having reference to the direction of looper rotation, themember E is formed with an inwardly extending lug E3, which has itsinner end received in an opening B6 formed in the bottom Wall of therecess B5, and defines a loop receiving throat. Adjacent its forwardend, the member E is formed with an inwardly extending flange portionE4, which constitutes a front side portion of the spur E2. The forwardend of the flange E4 extends into a radial kerf Brl formed in theforward edge o-f the notch B2.

The front side of the flange portion E4 is thus disposed to the rear ofthe front edge portion 56 B10 of the hook ring which is angularly inadvance of the notch B2, as clearly appears in Fig. 1A. In consequence,as the hook moves into the position at which a loop is being discharged,from the spur E2, the limb of that loop which, as a result of the looptaker movement, passes out of engagement with the edge B10 and intoengagement with the portion E4 of the spur E2, has no opportunity to becaught by any corner or edge of the member E. With the integral portionsE3 and E4, adjacent the opposite ends of the member E, thus received inopenings formed for the purpose in the hook ring B, the member E isaccurately and securely anchored in place and the adjacent threadguiding surfaces of the member E and hook ring B are properlyl related.

The front edge of the hook ring B is extended to form a loop throw oishoulder B8' which trails the hook B and terminates about 180 back ofthe hook. Adjacent its front side, the hook ring is formed with aninwardly extending circumferential flange B9 alongside, but spaced awayfrom the front end of the rim portion A2 of the hook spider A. Thegroove-like space thus provided between the end of the flange A2 andflange or shoulder-B9, is open at its innerside, and receives theperipheral guide flange D of the non-rotatable bobbin carrier D aboutwhich a needle thread loop is carried by the hook B in each stitchforming operation. The bobbin carrier D as shown, comprises a centralpost D2 on which the usual bobbin (not shown) is mounted. The bobbincarrier D is also formed at its front side with a pair of radiallyextending thread deflecting flanges D3 and D4 which extend radiallyoutward beyond the peripheral edge of the ilange D', each for aconsiderable angular distance about the axis of the bobbin carrier. Theadjacent end of the anges D3 and DL1 are spaced apart to form a notchreceiving a nger part (not shown) for holding the carrierV againstrotation and with its needle opening above the axis of the post D2.

The bobbin carrier D is not novel, but on the contrary, is of a type andform which is now and long has been in extensive commercial use. Whileno novelty is claimed in the form or construction of the carrier D, myimproved loop taker is characterized by provisions permitting such abobbin carrier of given size to'be used in a loop taker includingseparable hook ring and spider parts, smaller in diameter' than would berequired but for said special provisions.

The latter consists of notches B10 and B11 formed in the innerside ofthe hook ring member B, which extend in the general direction of, andare located at the opposite sides of the axis of the hook ring. Thenotch B10 is formed in the portion of the hook ring at the rear of thehook notch B2. The notch B11 is formed in the flange B9,

and as shown, is of a depth approximately equal to the radial extent ofsaid flange.

With the notches B10 and B11 arranged as shown, it is possible to warpthe bobbin carrier D, as shown in Fig. 4, into and out of its normalposition within the hook ring B, when the latter is disconnected fromthe spider A, without requiring the main cylindrical inner surface Yofthe hook ring to have a diameter signicantly greater than that of thecarrier Yrib D. The fact that the notch B10 is at the rear of the hooknotch B2,

.is advantageous since, as shown in Fig. 2, the

cylindrical inner surface of the member E which bridges the notch B2, isfarther fromthe axis of the hook ring than is the bottom of the notchB10.

carrier D.

- quired for the separate formation of hook ring and spider parts of thegeneral character of the parts B and A, than is required for theproduction of a loop taker includingv corresponding parts integrallyconnected. While the advantages of the loop taker comprising separatelyformed hook ring and spider parts have long been recognized, thecommercial use of such loop takers has been restricted, because of thepractical difliculties in the way of mounting a suitable bobbin carrierin the loop taker and of providing the latter with thread deflecting orcontrolling parts corresponding to applicants parts E, E2, and B8, andsuitably disposed and of suitable strength without making the loop-takersignicantly larger than it needs toy be when its hook ring and spiderportions are integral, or when the loop taker is constructed as hereinprovided for. Y

While all the novel features of the present invention are adapted forconjoint use in a loop taker comprising separable hook ring and spiderparts as shown in Figs. 1-5, the detachable member E, with its loopdeflecting edge E and the loop discharging spur E2, may be used in aloopl taker, AB, as illustrated in Figs. 6 and 7, having integrallyconnected hook ring and spider portions. As the general construction ofthe loop taker AB forms no part of the present invention and is wellknown, it need not be described herein. It is noted, however, that linsuch a loop taker, the bobbin carrier D is removably secured inoperative relation to the loop taker AB, by means of a retaining ring Fsecured by screws F against a surface of the member AB transverse to theaxis of the latter. in the assembled condition of the loop taker shownin Figs. Gand '7, the ring F forms the front wall of the annular .groovein the loop taker receiving the rib D of the bobbin In rthe constructionshown in Figs. 6 and r1,'the ends of the loop taker E are secured to acylindrical portion AB' of the member AB just as they are secured to thehook ring B of the construction first described, the member AB beingformed with an opening B0 for the projection E3 and with a groove B",like the opening B5 and groove B7 previously described.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is: f

l. A new article of manufacture comprising a one piece metallic partadapted for attachment to the hook ring portion of a rotary hook sewingmachine in bridging relation with the hook notch thereof, and comprisinga body portionV having an inclined front edge portion adjacent one endadapted to form `one side of a thread loop receiving throat having itsother side formed by the hook portion of said-hook ring and formed atits other end with a loop discharging spur adapted to deilect rearwardlythe limb of a thread loop lili passing out of engagement with the rearedge of said hook in the nal portion of a stitch forming operation.

2. `A new article of manufacture comprising a one piece metallic partadapted for attachment to the hook ring of a rotary hook sewing machinein bridging relation with the hook notch thereof and comprising a bodyportion of cylindrical arc form and having an inclined front edgeportion adjacent one end and adapted to form one side of a thread loopreceiving throat having its other side formed by the hook portion ofsaid hook ring and formed at its other end with a loop discharging spuradapted to deflect rearwardly the limb of a thread loopv passing out ofengagement with the rear edge of said hook in the final portion of astitch forming operation, said part also comprising an inwardlyextending flange portion at the front edge of its said other endconstituting a portion of said spur.

3. A rotary loop taker for a sewing machine comprising a hook ringportion formed with a.

hook and hook notch, and a part detachably connected to said ringportion in bridging relation with said notch, and formed with a frontedge portion alongside and at the rear of said hook and uniting with thelatter to form a thread loop limb receiving throat, andformed adjacentits opposite end with a loop discharging spur facing said hook andadapted to deflect rearwardly the said thread loop limb when the lattermoves away from the hook in the final portion of the stitch formingoperation in which said loop is formed.

4. A rotary loop taker for a sewing machine comprising a hook ringportion formed with a hook and hook notch, and a part detachablyconnected to said ring portion in bridging relation with said notch andformed with a front edge portion alongside and at the rear of said hookand uniting with the latter to form a thread loop limb receiving throatand formed adjacent its opposite end with a loop discharging spur facingsaid hook and adapted to deflect rearwardly the said thread loop limb asthe latter is moved away from the hook in the final portion of thestitch forming operation in which said loop is formed, said part beingformed with an inwardly extending flange portion forming the front sideof said Vspur and said hook ring portion being formed with a radiallyextending groove opening from the edge of said notch adjacent the baseof said spur and adapted to receive a portion of said flange.

5. A loop taker for a rotary hook sewing machine comprising an annularhook ring part formed with a hook notch, and with a hook at its frontedge, and with an inwardly extending circumferential flange adjacent itsfront edge,

and a rhub part including a cylindrical .portion adapted to extend intoand be detachably secured within said hook ring with the front edge ofsaid cylindrical portion spaced away from they said flange to form acircumferential guideway, a non-rotatable bobbin carrier formed with aperipheral guide rib adapted to be received in said guideway and formedwith a thread guiding portion at its front side overlapping said flangewhen said rib is received in said guideway, said ring being formed withdiametrically opposed internal notches, one of which extends irough saidflange, whereby when said hook ring and said hook part are separated,said carrier may be moved into and out of the position in which saidthread guiding portion is in front, and said rib at the rear of andalongside said flange.

6. A loop taker for a rotary hook sewing machine comprising an annularhook ring partA formed with a hook notch, and with a hook at its frontedge, and with Van inwardly extending circumferential ange adjacent itsfront edge, and a hub part including a cylindrical portion adapted tokextend into and be detachably secured within said hook ring with thefront edge of said cylindrical portion spaced away from the said flangeto form a circumferential guideway, a non-rotatable bobbin carrierformed with a peripheral guide rib adapted to be received in internalnotches, one of which extends rear" Wardly from the front edge of theportion of the hook ring at the rear of said'notch and the other ofwhich extends through said flange, whereby when said hook ring and saidhook part are separated, said carrier may be moved into and out of theposition in which said thread guiding portion is in front and said ribat the rear of and alongside said flange. l

V'7. An article of manufacture consisting of an annular one piece part,adapted for use as a detachable hook ring part of the loop taker of arotary hook sewing machine, and formed with an inner cylindrical surfaceadapted to receive and snugly surround the peripheral portion of rthehub port of the loop taker, and formed with ing a front edge portionextending away froml the base of said hook and diverging away from theplane of rotation of the hook to form a thread deflect or.

RICHARD K. HOHMANN.

